Don't know what has happened.

[Bogeyman68]

Last year and it looks like the start of this year something has happened. I feel as though I am coming across the ball. Be honest I am not totally sure what is going on. I played yesterday and the round started great. About mid round my follow through seemed to get shorter almost like a punch shot follow through and and balls sliced right. I even hit a few thin irons. I could not correct it. I do not know if it was fatigue or what. It has got to the point that I would rather play alone than have these first time golfer mistakes show up with friends. I wish I could get video but I never know when it is going to happen. It is very discouraging and embarrassing.

[WUTiger]

I played yesterday and the round started great. About mid round my follow through seemed to get shorter almost like a punch shot follow through and and balls sliced right. ...

Might be a problem with flexibility. Did you have a chance to work out over the winter?

Or, you could have strained your back muscles if you didn't warm up well on a cold, spring day. It's early in the year. If this problem persists, you might consider a tune-up lesson to diagnose the problem.

[Neco]

It could be any number of things but by chance, have you extended your backswing by accident trying to hit it farther?

Going back to far can cause funky things to happen on the way down.

[westcyderydin]

i would check to make sure that your chest is staying "down at the ball" at impact and that your right shoulder isnt dropping or your right side isnt collapsing. you should feel more like a tower than a big C. look at WUtigers avatar (directly below your original post). the guy looks like a tower at that position and now is when he will start to turn his hips. if youre hips are already turned at this point (or if they are slid forward too far) you will come over the top and will have a problem squaring the clubface. that may be why you are coming across the ball and slicing it and why your follow thru is feeling wack.